<http://schema.org/image_url>
"http://media.masslive.com/sports_impact/photo/49ers-football-stadium-super-bowljpg-6ba9bf5de2699231.jpg"^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.masslive.com/sports/index.ssf/2013/05/upcoming_super_bowl_50_51_site.html>